1. Field of the Invention
The present invention relates to a display device and electronic equipment having the same, and especially relates to a structure of a display body capable of switching a display screen into a mirror mode.
2. Related Art
Hitherto, there has been known a display device which is switchable between a normal display mode and a mirror mode by overlapping two liquid crystal panels. For example, there is a display device in which a display switching unit is provided on the observation side of the display unit having the same structure as that of a typical liquid crystal display device, and a reflective polarizing plate, a liquid crystal panel, and an absorptive polarizing plate are disposed in the display switching unit in this order from the side of the display unit. In this display device, the reflective polarizing plate of the display switching unit transmits the first polarization component and reflects the second polarization component having a polarization axis intersecting with the first polarization component, the liquid crystal panel is designed to be switchable between a state of transmitting light after changing the first polarization component into the second polarization component and a state of transmitting light without changing the polarization axis, and the absorptive polarizing plate transmits, for example, the first polarization component and absorbs the second polarization component. The display unit emits the first polarization component to the display switching unit and a predetermined display image is formed by the first polarization component.
In the display device constituted as described above, when the liquid crystal panel of the display switching unit is in the transmissive state without changing the polarization axis, the first polarization component emitted from the display unit passes through the reflective polarizing plate to enter the liquid crystal panel, and is observed as it is as the first polarization component after passing through the absorptive polarizing plate. Thus, it is possible to visibly recognize the display condition of the display unit (display mode). In the transmissive state of the liquid crystal panel, which changes the first polarization component into the second polarization component for transmission, when the first polarization component emitted from the display unit passes through the reflective polarizing plate to enter the liquid crystal panel, it is changed into the second polarization component and therefore, it is absorbed by the absorptive polarizing plate, and the display condition cannot be visibly recognized. When outside light enters into the device at this time, the outside light passes through the absorptive polarizing plate, hence to be the first polarization component, and it passes through the liquid crystal panel, hence to be the second polarization component. Therefore, it is reflected by the reflective polarizing plate, changed into the first polarization component after passing through the liquid crystal panel again, and passes through the absorptive polarizing plate. Accordingly, the display surface is visibly recognized as a mirror surface (mirror mode).
In the above-mentioned conventional display device, however, the light transmitted through the liquid crystal panel provided in the display switching unit, is visibly recognized in both the display mode and the mirror mode. Therefore, there are problems such that contrast is deteriorated due to a boundary reflection in both sides of the display switching unit, coloring caused by the optical characteristic of the display switching unit, the characteristic of the viewing angle is deteriorated, and blurring of a display image easily occurs. In any case, the conventional display device cannot avoid deterioration of the display quality caused by the double structure of the display unit and the display switching unit.
The present invention attempts to solve the above problems, and one object of the invention is to provide a new structure of a display device having a display unit and display switching unit, capable of restraining the deterioration of the display quality including contrast deterioration, coloring, reduction of viewing angle, and blur caused by the existence of the display switching unit.